arch

Definition of ARCH

1

: an anatomical structure that resembles an arch in form or function: as a: either of two vaulted portions of the bony structure of the foot that impart elasticity to it: (1): a longitudinal arch supported posteriorly by the basal tuberosity of the calcaneus and anteriorly by the heads of the metatarsal bones (2): a transverse arch consisting of the metatarsals and first row of tarsals and resulting from elevation of the central anterior portion of the median longitudinal arch b:arch of the aorta

2

: a fingerprint in which all the ridges run from side to side and make no backward turn